"You just don't get it," he told thousands of bankers on more than one recent call, according to bankers who were on the call.

"He told us that bankers are spoiled children and we're the ones who messed this place up," said one senior banker who recently left the firm. "You would get off the calls and think, 'how can I stay here any longer?'"

It's apparently comments like this that have resulted in the flight of top talent from the bank; 13 high-level bankers have left the firm since the new year.

Those comments and "low pay, albeit by Wall Street standards, sagging morale and a disconnect between UBS headquarters in Zurich and the New York-based investment-banking unit" are driving bankers away.

There's apparently a feeling in the bank here that there is "a deliberate attempt to starve the operation" in the US, the WSJ reports.